Definition of cylindrical grinding process standard for aeronautical gears

Grinding is a key technology in metal manufacturing process because it can ensure required surface finish where other manufacturing process may have difficulty meeting product requirements. Grinding is applied in finishing stages of product manufacturing cycle when the value of the machined part is already significant and where mistakes can be very expensive. Besides accuracy of dimensions and surface finish, grinding also influences physical layer properties such as residual stress, hardness and microstructure during the material removal process leading to high risk of a thermal damage of the part surface layer. Grinding is a high-added value manufacturing process. In today's global manufacturer competition, companies that deliver high value in manufacturing have strong financial performance also because of their high quality recognition. However they must constantly improve their performances first of all in terms of quality and delivering time to maintain leadership in their business. This becomes possible only innovating, inventing, investing in Research and Development and last but not least investing in people knowledge. This thesis has been developed in collaboration with Avio Aero, Global Supply Chain in Rivalta plant. Avio Aero is a GE Aviation business that designs, manufactures and maintains components and systems for mechanical transmissions, turbines and combustors. Through continuous investment in research and development and a consolidated network of relationships with major Universities and international Research Centers, Avio Aero has developed a technological and manufacturing excellence globally acknowledged. The aim of this thesis was to define a cylindrical grinding process standard for aeronautical gears in particular for grinding of case hardened steel bearing race. The study has been conducted mainly on four phases, that means my gradual growth in grindology. The first was a deepened study of grinding process and in the meantime the knowing of aeronautical product in particular gears, the second was a meticulous data collection of current grinding process from the company, the third was a careful analysis of gathered data, and the fourth was a multiple approach to improve the current process looking at the grinding in itself but also at the technologists needs, supporting them in the grinding parameters definition.